Both the law and practical safety considerations require or suggest that a person be able to exit a basement through a direct route to the outside. This is particularly important in times of emergency, such as during fires or even earthquakes. This is commonly accomplished via subterranean windows with removable sashes to provide an egress port. These are sometimes herein referred to as subterranean egress windows. These subterranean windows require adequate size to allow the passing of a human being. In many jurisdictions there are specific size requirements for egress windows to escape from the basement or similar partial or fully subterranean location.
In order to assure adequate space on the outside of the window, the area adjacent to the window is typically dug out and walled off. This is commonly done with preformed corrugated metal window well shells. Such window well shells help to sustain a window well which is an opening, void or space of adequate size to allow passage by a human from the basement or the structure.
Window well shells are commonly installed so as to have a rim extending several inches above ground level to help prevent water and debris from easily dropping into the well. This rim creates a tripping hazard which is unsafe. There has been a long-felt need to prevent people from inadvertently tumbling into such window wells and still not pose a hindrance to escape. The known prior approach has been to place a relatively heavy grate which merely rests upon the upper rim of the window well shell.